Some loading docks of a building include an exterior doorway with an elevated platform for loading and unloading vehicles, such as trucks and trailers. To compensate for height differences between the loading dock platform and an adjacent bed of a truck or trailer, many loading docks have a dock leveler. Some dock levelers include a deck or ramp that is pivotally hinged along its back edge to vary the height of its front edge. An extension plate or lip extends outward from the deck's front edge to span the gap and thus create a bridge between the rear of the truck bed and the front edge of the deck. This allows personnel and material handling equipment to readily move on and off the vehicle during loading and unloading operations.
If the truck or trailer is enclosed, as opposed to being an open flat bed trailer, the inside of the trailer can be quite dark, making it difficult to see deep inside the trailer. So, a light fixture pointing into the trailer can be installed and used near the doorway of building. Such light fixtures are available in various shapes and sizes.